Vacuum pole sander

ABSTRACT

A sanding device for working with gypsum board (sheetrock) and which may be coupled to a vacuum cleaner to reduce the dust problem created when sanding the joint cement. The sanding device comprises a sanding head having a generally rectangular planar base with a pattern of pedestals formed thereon for supporting the abrasive material. The base defines a vacuum plenum having ports therethrough for placing the channels between adjacent pedestals in fluid communication with the vacuum chamber. The head member is configured to attach by a universal joint to an elongated tubular pole whereby the workmen can manipulate the sanding head high on a wall or ceiling from a position on the floor. The vacuum cleaner is connectable to the free end of the pole and a suitable hose connection is made between the hollow interior of the tubular pole to the vacuum chamber of the sanding head.

BACKGROUND OF THE INVENTION

I. Background of the Invention:

This invention relates generally to an improved device for creatingsmooth joints between sheets of gypsum-type wallboard, and moreparticularly to an improved gypsum board sanding tool incorporating adust collecting feature.

II. Discussion of the Prior Art:

In my earlier U.S. Pat. No. 4,779,385, there is disclosed a pole sanderof the type involved herein in which a hollow tubular pole provides theconduit through which a vacuum may be drawn creating a negative pressurethrough and around the base and side surfaces of a sanding head. Thesanding head is fastened to the pole by means of a universal joint and aflexible, air impervious boot is made to surround the universal jointand the lower end portion of the pole. A somewhat similar configurationis discussed in the Mehrer U.S. Pat. No. 4,062,152.

My earlier construction was found to exhibit certain drawbacks. Moreparticularly, with only a single central opening through the back of thevacuum chamber, a lack of uniformity in the amount of vacuum developedover the working face and edges of the sanding head has been observed.Moreover, being disposed in the fluid path, the universal joint isexposed to all of the dust and debris being drawn through the sandinghead and the tubular pole to the vacuum cleaning attachment. The buildupof dust and debris in the universal joint was found to prematurely wearthat joint because of the abrasive properties of that dust.

It has also been found that the accordian-pleated boot used to surroundthe U-joint and to provide a air-tight seal between the sanding head'svacuum chamber and the interior of the hollow pole tended to be overlyflexible allowing the sanding head to flip and flop about too freely,making it somewhat difficult to maintain the desired surface contactbetween the abrasive sheet and the wall being treated.

The device of the Mehrer patent suffers from a further drawback in notadequately providing a fluid path between the perimeter of the sandinghead and the vacuum chamber. As such, only the dust and debris developedover the planar surface of the sanding head is picked up and thatsurrounding the perimeter falls free.

SUMMARY OF THE INVENTION

Like my earlier gypsum board sanding apparatus, the present invention isdirected to a sanding tool for smoothing and finishing the plasterjoints between sheetrock panels such that the amount of dust developedwhich would otherwise permeate the area is collected in a vacuumcleaner. In accordance with the present invention, there is provided aflat, planar base member having first and second vacuum ports formedthrough the thickness dimension thereof at predetermined spaced-apartlocations. The base member includes four mutually perpendicular sideedges which fit about a planar, rigid, air-distribution member to yielda vacuum chamber. The air-distribution member includes a pattern ofapertures extending through it. Suitably attached to the outside surfaceof the air-distribution member is an array of raised pedestals, all ofequal height, and located so as to define interconnected channelsleading from the periphery of the air-distribution member to the patternof apertures. An elongated tubular pole having an open end and a closedend is joined to the planar base member by a suitable universal jointwhich permits the sanding head to be positioned over a wide range ofangles relative to the axis of the elongated pole. Formed through thewall of the pole proximate its lower end are a pair of side ports.Flexible hoses are then used to couple those side ports on the pole tothe vacuum ports formed on the base member. The hoses, while flexible,are sufficiently rigid to restrain free movement of the base memberrelative to the tubular pole and, moreover, provide a fluid path fromthe interior of the vacuum chamber to the interior of the tubular pole.

The hoses also bypass the U-joint so that, unlike my earlier embodimentdescribed in U.S. Pat. No 4,779,385 and the arrangement shown in theMehrer Pat. No. 4,062,152, the universal joint is not in the path offlow of the dust created during the sanding operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective drawing of the sanding head portion of the polesander of the present invention;

FIG. 2 is a partially cross-section side view of the pole sander; and

FIG. 3 is a view of the sanding head taken along the lines 3--3 in FIG.2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As is plainly illustrated in the views of FIGS. 1 through 3, the vacuumsander in accordance with the present invention includes a generallyrectangular base member 12 having four mutually perpendicular downwardlydepending side walls as at 14, 16 and 18. The remaining side wall 19(FIG. 2) has been cut away in the drawing to better illustrate theinterior of the base member 12.

Affixed to the lower edge surfaces of the four side walls 14, 16, 18, 19and extending parallel to the base member 12 is a rigid, rectangular,generally planar, air-distribution member 20. As best illustrated inFIG. 3, the air-distribution member 20 includes a plurality of aperturesas at 22 arranged in rows and columns and spread rather uniformly overthe planar surface of the member 20.

Secured to the exposed underside of the air-distribution member 20 aboutits peripheral edges are a plurality of pedestals, as at 24, which areof equal height and which provide spaces therebetween defining aplurality of channels. Further cylindrical pedestals as at 26 aredistributed over the surface of the air-distribution member 20 such thata piece of abrasive sheet material (not shown) when draped over theunderside of the pedestals 24 and 26 will be spaced apart slightly fromthe matrix of apertures 22.

Referring again to FIGS. 1 and 2, it is to be observed that first andsecond spaced-apart vacuum ports, as at 28, pass through the thicknessdimension of the base member 12 and surrounding those two ports aretubular stubs 30 and 32. Flexible, accordian-pleated hoses 34 and 36 arefitted over these respective stubs and are joined at their other end tosimilar tubular stubs 38 passing through the wall of a tubular couplingmember 40. The hoses 34 and 36 are preferrably fabricated from aflexible plastic material reinforced with a helical wire and ofsufficient stiffness to limit or control the base member 12 fromflip-flopping relative to the pole.

The coupling member 40 is closed to air flow at its base 42 and auniversal joint, indicated generally by numeral 44 is used to fasten thetubular coupler 40 to the upper surface of the base member 12. Theuniversal joint is of conventional design and includes two orthogonallydisposed axes 46 and 48 to allow the angle between the coupler sleeve 40and the base member 12 to be continuously adjustable over apredetermined range. An elongated tubular pole 50 may be received in thecoupler 40 either with a friction fit or by a threaded connection.

To hold the abrasive sheet (not shown) taut over the undersurface of thepedestals 24 and 26, a suitable clamping means, as at 52 and 54, areprovided. As best seen in FIG. 1, these clamps preferably comprise asheet of spring steel cut so as to be generally U-shaped, with parallellegs 56 and a cross portion 58 connected between them. The legs 56 arefastened to the base member by screws or rivets, such as at 60, suchthat a bent vertical edge 62 of the clamp members is normally urgedtightly against the upper surface of the base member 12. Levers, as at64, are inserted through slots 66 formed in the U-shaped clamping platesbefore those plates are fastened to the base member. The levers arearranged such that when the exposed portion thereof is lifted upwardrelative to the base member, it serves to also pry the vertical edge 62of the spring plate away from the base member so that an abrasive sheetmay be slipped between the two. When the lever is again released, theclamping force of the spring plate holds the abrasive sheet againstmovement during the sander's use.

With continued reference to FIG. 1, the right end edge 19 of the basemember 12 is broken away to better illustrate the way in whichreinforcing ribs on the air-distribution member 20 function to preventthe air-distribution member from deforming into the interior of thevacuum chamber as sanding pressure is applied between the pole sanderhead and the surface being finished. More particularly, a series ofribs, as at 68, are integrally formed with the air-distribution member20 and extend parallel to one another over the length dimension of thesanding head. The height of the ribs is such that the air-distributionmember 20 is maintained in parallel, spaced relationship with respect tothe surface of the base member 12.

This invention has been described herein in considerable detail in orderto comply with the Patent Statutes and to provide those skilled in theart with the information needed to apply the novel principles and toconstruct and use such specialized components as are required. However,it is to be understood that the invention can be carried out byspecifically different equipment and devices, and that variousmodifications, both as to the equipment details and operatingprocedures, can be accomplished without departing from the scope of theinvention itself.

What is claimed is:
 1. Sanding apparatus comprising:(a) a sanding headincluding(i) a generally rectangular planar base member having first andsecond vacuum ports formed through the thickness dimension thereof atspaced-apart locations on either side of a transversely extending centerline, said base member having four mutually perpendicular side edges;(ii) a rectangular planar, rigid air-distribution member cooperatingwith said four side edges and said planar base member to create a vacuumchamber, said air-distribution member including a pattern of aperturesextending therethrough; (iii) an array of raised pedestals of equalheight extending outwardly from said air-distribution member to defineinterconnected channels leading from the periphery of saidair-distribution member to said pattern of apertures, said array ofpedestals adapted to support a perforated abrasive sheet member thereon;(b) an elongated tubular pole having an open end and a closed end andjoined to said planar base member of said sanding head by a universaljoint disposed at said closed end and with first and seconddiametrically opposed side ports extending through the wall of saidtubular pole a predetermined distance proximal of said closed end; and(c) a pair of flexible hoses coupled individually and bilaterallysymmetrically relative to said planar base member between said first andsecond side ports and said first and second vacuum ports, said pair offlexible hoses being sufficiently rigid to restrict free movement ofsaid base member relative to said tubular pole while allowing pivotingof said sanding head relative to said pole about two mutuallyperpendicular axes when said sanding head is pushed with a predeterminedforce against a surface to be sanded, the arrangement being such that asource of vacuum coupled to said open end of said tubular pole creates arelatively uniform negative pressure within said vacuum chamber.
 2. Thesanding apparatus as in claim 1 and further including clamp means onsaid base member for removably securing said abrasive sheet in positionon said array of pedestals.
 3. The sanding apparatus as in claim 2wherein said clamp means includes a sheet of spring steel secured to theouter surface of said base member proximate opposed end edges thereofand normally biased against said outer surface, and lever means forlifting said sheet allowing a portion of said abrasive sheet to beinserted in between said sheet and said outer surface of said basemember.
 4. The sanding apparatus as in claim 1 wherein said universaljoint includes a tubular sleeve dimensioned to telescopingly receivesaid elongated pole and having a pair of mutually perpendicular pivotaxes affixed to said tubular sleeve and to said base member to allow theangle between said sleeve and said base member to be continuouslyadjustable over a predetermined range.
 5. The sanding apparatus as inclaim 1 wherein dust developed during a sanding operation is drawnthrough said channels and said pattern of apertures into said vacuumchamber and thence through said flexible hoses and said tubular pole tosaid source of vacuum.
 6. The sanding apparatus as in claim 5 whereinsaid universal joint is outside of said vacuum chamber and not exposedto the flow of dust.